Artificial tooth



Oct. 1, 1940.

A. WERKE INTHIN ARTIFICIAL TOOTH Filed Nov. 9, 1937 2 Sheets-Sheet l 11v VEN T077 Oct. 1, 1940.

A. WERKENTHIN ARTIFICIAL TOOTH Filed Nov. 9, 1931' 2 SheetsSheet 2 Patented Oct. 1, 1940 UNiT D1 STATES ARTIFICIALTOOTH Albert Werkenthin, Berlin-Wilmers dorf,

Germany a Application November 9, 1937, Serial No. 173,661 In Germany November 19, 1936- 4 Claims.

This invention comprises improvements relating to artificial teeth and concerns teeth consisting of porcelain bodies which are united by anchoring members to tooth carriers consisting of metal or non-metallic material, depending upon whether it is a matter of metal work or rubber work. Known artificial teeth of this kind serving for metal work, such as crown or bridge work, have the disadvantage that the anchoring members are constructed as resilient members which must be made from expensive materials, for example platinum-gold, and moreover can exert their resilient action-only by virtue of a complicated construction similar, say, to a press button. They contact only point-wise with the headed or knobbed anchoring pins of the porcelain bodies, so that there must be a thorough filling of all interstices with tooth-cement for the purpose of embedding in an enclosing member which is constructed like a small box and is to be connected to the metal tooth-back. Such a filling with tooth-cement, is known, however, to exercise a destructive influence upon the metal of the anchoring pins and prevents the cement from acting, in accordance with its proper function, as a surface-connecting means, that is of acting as a cement in the narrow sense.

On the other hand it is also known to provide the enclosing body, as such, with gripping members which engage behind and under the knobs of the anchoring pins. In this case, if no tooth-cement is employed, there is the disadvantage, firstly that a comparatively large empty space is formed around the anchoring pins in which, if there is the least lack of tightness, juices from the mouth will collect and decompose, and secondly that the small box set upon the anchoring pins cannot be removed again without being destroyed even if it has only been fitted once in the patients mouth for trial purposes.

Finally it is known "to produce, around the anchoring pins, a cast body of tin which is then likewise embedded in a recess of suitable form in the tooth-back without however the provision of a separate enclosing body to be cast therein. This construction has the disadvantage that it is diflicult to produce the cast body and that the soft metal does not sufiiciently resist the pressure exercised by the bite upon the porcelain and does not sufficiently resist the acids of the cement. Furthermore it is undesirable to effect the casting directly against the porcelain body. The invention obviates all the foregoing disadvantages, and provides an artificial tooth which can be used both for metal work and. for rubber work and it consists essentially in mounting on the rear side of the porcelain body a hard metal "block which becomes embedded in the toothcarrier; r a For metal work, the usual anchoring pins on the porcelain front form together with shaped parts a metal block free from hollow spaces, the shape and size of this block being in every case appropriate for fitting into the hollow space in the enclosing body in which the block is cemented. The individual shaped parts do not need to be cemented to one another orto the anchoring pins, for the enclosing body, which may be a small box-like part, may-by itself be capable of holding firmly together theparts forming the block, particularly as there exists a sound connection between the two, after the embedding of the enclosing body by casting in a metallic tooth-back.

With a construction in accordance with this invention, therefore, there is no formation-of any deposit of tooth-cement and consequently no deleterious influence of such deposit upon the metal of the anchoring pins. Naturally, also, a trial assemblage of all the parts of the tooth'is possible without difiiculty until the cementing of the enclosing body to the composite block has been eifected- I l Advantageously, the parts composing the metal block are shaped so that a rectangular block is formed, the parts being held together and: to the anchoring pins. By this means, not only is thecoherence of the block improved, but also the work is facilitated for the dentist, particularly if it should be necessary to perform. a repeat fitting of the assembled metal block in the enclosing body united to the tooth-back.

The block parts are provided with lateral recesses :ior accommodating the anchoring pins, andmay be secured by pressing them apart and against the anchoring pins, by the insertion of an intermediate, piece which may act after the fashion of a wedge or as, a securing member and which maybe made of hard metal like the shaped parts themselves. If the block parts aremade of hard metal containing silver, the intermediate layer may consist of an amalgam which, as is known, can be introduced in a plastic condition in order to be hardened subsequently to a high degree. According toa modification, the block parts may be secured together andto the pins by screws or rivets. I g v i Further, in accordance with the invention, the anchoring means for the porcelain body or facette is constructed from the startas a unitary metal block which again fills the hollow space in an enclosing body and is cemented in the latter. Such a construction simplifies the work for the dentist without making the manufacturing production of the porcelain body more difficult and, moreover, all the advantages of the first-described construction are retained.

The manufacturing production of the porcelain body may be further simplified, in that it is sufficient for the metal block to-be anchored in the porcelain material with one pin only, provided that this pin or its anchoring members have a shape which prevents turning movement of the pin, and consequently of the metal block, in relation to the porcelain body.

The metal block is advantageously of rectan gular form, because the mounting in the enclosing body, or the fitting of an enclosing body to be produced by the dentist, can then be performed in the most simple fashion. It is best for the rectangularly shaped block to have the same widths and depths in all cases and for its length only to vary according to the dimensions, particularly the width, of the porcelain body. It then remains fundamentally immaterial whether or not the principal dimensions of the block extend in the same direction as the principal dimension of the porcelain body. Thus, the block may lie either transversely or longitudinally in relation to the porcelain body, depending upon whether. the tooth is very narrow or has sufiicient width.

Teeth constructed in accordance with this invention may be employed both for crown and bridge work (also for metal plates) and also for rubber work wherein the porcelain bodies are vulcanizedon .to a palate plate. For this latter case, however, a change is preferably made in that undercut surfaces are provided on the block, so'that' the 'block is then anchored in the vulcanized rubber, for example after the fashion of a dovetail. Teeth serving this particular purpose may be supplied from the start with undercut block-sides. The production of these undercuts, however, may be equally well left to the dentist who has available the tools necessary for the purpose. For example he can produce the undercuts at the sides by means of a fret-saw. He may also himself out out, for example, a dovetail recess from the block in which case it. is certainly to be recommended that such porcelain bodies should be selected having blocks fixed in the porcelain material with two pins in orderto avoid any excessive stressing of the block or its anchoring means. If the porcelain tooth-body is supplied from the manufacturers with a block provided from the start with a recess or recesses, it is naturally suitable initially only for rubber work. If, however, it is desired to use it for metal work, that is for crown and bridge work, then a hard metal body of suitable shape must be inserted in the recess in question, with or without the use of binding agents, in order that the block shall again fill the whole empty space in the enclosing body necessary formetal work. Such complementary bodies may'also be supplied at the same time, forexample as fitting pieces for recesses of dove tail shape. For rubber work, on the other hand, the metal block, without a separate enclosing body, may be vulcanized to a palate plate, whereas for metal work an enclosing body is employed. Various embodiments of the invention by way of exampleare illustrated in the drawings. Further features of the invention will appear from the following description of these embodiments:

Fig. 1 is a rear elevation of a porcelain body with anchoring pins and a composite block.

Fig. 2 is a rear elevation of a porcelain body with a different form of block.

Fig. 3 is a vertical section approximately on the line a-a in Fig. 1 or b-b in Fig. 2 but showing also a metal tooth-back on the porcelain and an enclosing body for the block.

Fig. 4 is a perspective view of the rear side of a porcelain body such as is seen in Fig. 1 with an enclosing body, partially cut away, placed over the block.

Fig. 5 is a perspective View to a larger scale of a pair of shaped parts such as is seen in Figure 1. Fig. 6 is a perspective view of a set of plates of different thicknesses to be used for wedging or securing the shaped parts of Fig. 5.

Fig. 7 is a perspective view of a divided enclosing body for the blocks.

Fig. 8 is a rear elevation of a porcelain body fitted with a sanitary anchoring block.

Fig. Qisa vertical section on the line 0-0 in Fig. 8, but showing the porcelain body mounted on a carrier.

Fig. 10 is a perspective viewof a. porcelain body and block-such as is seen in Fig. 8. i

Figs. 11, 12' and 13 are perspective views of porcelain bodies with blocks provided with recesses and complementary parts for fitting into such recesses.

Referring to Figures land 2, the porcelain bodies or facettes have on the rear side, in each case, two anchoring pins 2 whose outer ends are constructed like knobs or screw-heads. In Fig. 1, each pin 2 has allotted to it a shaped block part 3 which receives the stem and head of the pin in recesses 4 of substantially corresponding shape. The two parts 3 lie between the pins and leave between them a free space 5 into which a plate -6 is forced straight in from above, in order to wedge .or .secure the parts 3 against the pins 2. If this body 6 lies wholly in the space 5, there is formed a beam-like block bounded by plane surfaces. The parts lot the pin-heads, projecting laterally beyond the block and illustrated by broken lines, may be filed off or ground off with discs of fine sandpaper.

Fig. 2 shows a modified block construction comprising upper and lower shaped parts 8 each furnished with a recess of suitable shape for each. of the two pins. .After the laterally projecting parts of the pin-heads (reference. numeral l in Fig. 1) have been ground off, there results again a beam-like block, bounded by plane surfaces. After mounting the composite block in a sheath, the parts thereof do not essentially require aseparate securing means because they cannot escape in any direction. However, by way of example, a securing screw 9 may be provided which can be passed through one of the parts 8 and screwed into the other, the first part having a countersink to receive the head of the screw 8.

In Figure 3 the porcelain body I is shown with a metal tooth-back I0 set thereon. It will be seen how the pins 2 lie embedded in the shaped parts 3 of Fig. 1 or the shaped parts 8 of Fig. 2. Over the block or beam thus formed, as described in connection with Figs l' and 2, is slid an enclosing body II which in turn rests in a recess l2 in the tooth-back Ill. The block is cemented-in the enclosing body II and this-in turn is castin the recess l2 in the tooth-back.

Fig. 4 shows the block formed by the shaped parts 3, Figure 1, the securing member 6, and the pins 2, the box-like enclosure H for the block being cut away to disclose the said parts.

The enclosing body H made of platinum, platinum-gold, palladium-silver, or cadmium, may be constituted by a hollow body of rectangular shape open at one of its surfaces only, which body may be supplied by the manufacturers, at the same time as the porcelain body I and the shaped parts 3 or 8, to suit the particular distances between the anchoring pins 2. However, the dentist may make it himself and it is sufficient to employ a length, open at both ends, of a U-section bar or strip of suitable metal. If, however, an enclosing body closed at the end faces is desired, then the two end faces may also be closed by simply applying at each end a small plate of the same metal shortly before'the modelling in cast wax.

In the parts 3 in Fig. 5 recesses l8 and 19 are formed into which the pins may be let in each case to the extent of say two thirds of their volume or diameter. Each part has a recess in one side, each recess comprising a cylindrical part to fit the stem of a pin and a conical countersink to receive the head. The remaining part of a pin protruding beyond the side of a block may be ground away. The recesses may however be made even deeper than for the two-thirds setting in of the pins. There then remain at the edges l3 only small insignificant gaps which can be eventually filled, with rubber, gold or tinfoil. Between the two shaped parts 3, there is a space 5 into which the securing body, for example one of the plates 6 shown in Fig. 6 may be inserted. The plates are of different thicknesses, as shown by Fig. 6, corresponding to the different distances that may be found between the pins 2. Thus, the shaped parts 3 may always have the same dimensions in spite of variations in the spacing between the pins.

Fig. '7 illustrates a divided enclosing body such as is shown at II in Figs. 3 and 4, which body may be made in one piece if desired. In the example illustrated it is constructed in three parts in order to enable the operator to produce an enclosing body of required length in each case by interposing middle parts 14 of different widths corresponding substantially to the thicknesses of the securing plates in Fig. 6. The joining of the individual parts of the enclosing body I! may, for example, be effected by embedding them together in the cast wax and then simply uniting them by the casting of the tooth-back in the wax. Naturally, however, it is also possible to have ready from the start enclosing bodies of three different sizes.

In Figs. 8 to 10, the porcelain body I has anchoring pins 2 which, however, form or hold a unitary metal block 3' outside of the porcelain body, this block being located closely against the rear face of the porcelain body.

As is evident from Fig. 9, an enclosing body H which is forced or cast into the metal tooth-back it is disposed over the block 2. The connection of the block 3 to the enclosing body II and consequently to the metal tooth-back i0 is effected simply by cementing surface to surface. The production of the enclosing body ll may be effected in the fashion already set forth. Its end faces may however remain open, so that the dentist may simply utilise a length of a channel section metal which fits over the cross section of the block 3 In Fig. 11 the block 3" is provided with a dovetail recess 20 which serves for keying or anchoring to rubber for example, without an enclosing body II or l4, Hi. If it is desired to employ this tooth for crown or bridge work, wherein the embedding in the tooth-back is effected with the employment of an enclosing body I'l, then the recess 20 must be refilled by a complementary body 21' of suitable shape with or without the use of a cement or binding material.

In Fig. 12 recesses 22 are formed in the en faces of the block 3|. These recesses may be, for example, perpendicular to the rear face of the porcelain body, but they may be disposed horizontally, as illustrated in Figure 13. In the example illustrated, the recesses 22 have the form of a hollow cylinder let into the ends to say threequarters of the total volume of such cylinders. Also in this case, direct anchorage in rubber may be effected with sufficient security, whereas, in the case of the use of the tooth for crown and bridge work, these empty spaces must be filled, for example by means of suitably dimensioned pieces of wire 23. The part of thewire pro jecting beyond the side faces of the block may then be filed away by the dentist if appropriately shaped pieces have not been supplied from the start.

The constructional forms illustrated in Figs. 1 to 3 take account of the shape of the anchoring pins which are at present provided on the porcelain bodies on the market. Naturally, however, the shape of the anchoring pins may take account of the embedding possibilities in accordance with the invention. This, however, may be left to future development.

Metals for the production of the shaped hard metal parts or the securing members are for example gold, palladium-silver, nickelin or a special brass (Randolf type). All of the parts may be made of the same material but this is not necessary. As it is frequently important to work in such fashion as to save labor and expense, which is readily possible in accordance with the invention, the shaped parts and/or the securing parts might be made, for example, of special brass or 16 ct. gold and the enclosing bodies of cadmium. If the shaped parts are made of palladium-silver, the enclosing body might be made of the same material. If the shaped parts are made of 16 ct. gold, the enclosing body may also be made of platinum. In the casting cadmium is replaced by gold. Palladium-silver must be used for palladium-silver and platinum for high value gold casting. The use of gold and platinum would merely be somewhat more expensive than the use of the other metals mentioned. This, however, has no great importance with the construction in accordance with the invention because there is a considerable saving of labor in the production of the block or beam, and of the connection generally, as compared with the known kinds of connection.

Many modifications are possible which, however, do not go beyond the scope of the invention.

I claim:

1. Artificial tooth comprising a facette, attachment pins embedded in the rear face of said facette, rectangular block parts engaged with said pins, securing means operatingbetween the block parts to prevent their displacement or disengagement from the pins, and a rectangular metal cover encasing the block assemblage.

2. Artificial tooth comprising a facette, attachment pins embedded in the rear face of said facette, two recessed rectangular block parts mediate layer of amalgam inserted between the block parts.

- 4. Artificial tooth comprising a facette, an choring pins in the rear face of said facette, a composite rectangular block consisting of two black parts engaged with said pins and an in.-

termediate spacer, and a cover for the composite block said cover comprising end lengths of channel section encasing the block parts and an intermediate length encasing said spacer.

ALBERT WERKENTI-HN. 

